This work studies the complementarity between hydro, wind and solar photovoltaic energy in the Brazilian state of Rio Grande do Sul. Brazil is a country highly dependent on hydro energy;however, the existent plants ar...This work studies the complementarity between hydro, wind and solar photovoltaic energy in the Brazilian state of Rio Grande do Sul. Brazil is a country highly dependent on hydro energy;however, the existent plants are not being able to cover the energy demand in recent years. In this context, the state of Rio Grande do Sul becomes important because of its potential for wind and solar photovoltaic energy, having complementarity between water, wind and solar photovoltaic schemes when hydroelectric reservoirs are at their lowest levels. This study aims to survey the complementarity of various parts of Rio Grande do Sul by proposing mathematical dimensionless ratios, focusing on intra-annual period to carry out a mapping of the entire state. It also analyses the ability to provide power supply throughout the year, through the stabilization of the energy supply, which depends on an adequate scale for photovoltaic, wind power and hydroelectric harnessing. According to the results obtained, the regions with the best complementarity indexes for deployment of a hybrid system in relation to water and wind power were the Metropolitan Region of Porto Alegre and the Southeast region, and the same regions also presented the best results for the complementarity between hydro and solar photovoltaic. Regarding wind and solar photovoltaic energy, the state’s northeast region presented the best results. Finally, the Northeast region of the state also presented the best results for the three energies together.展开更多
Energetic complementarity has been studied in recent years and can be an important tool for managers to decide on the design and operation of hybrid systems based on renewable energy resources. Complementarity is an a...Energetic complementarity has been studied in recent years and can be an important tool for managers to decide on the design and operation of hybrid systems based on renewable energy resources. Complementarity is an ability presented by two or more energy resources to complement each other over time. Complementarity can be verified in one place or at different places. This second case can be termed as spatial complementarity and is more complex than the complementarity in the same place, requiring a specific approach for its quantification This paper discusses concepts related to energetic complementarity and presents the basis for a method to evaluate energetic time-complementarity across space, applying the concepts presented to the northern coast of the state of Rio Grande do Sul, the southernmost state of Brazil.展开更多
A variety of landscape properties have been modeled successfully using topographic indices such as topographic wetness index (TWI), defined as ln(a/tanβ), where a is the specific upslope area and β is the surface sl...A variety of landscape properties have been modeled successfully using topographic indices such as topographic wetness index (TWI), defined as ln(a/tanβ), where a is the specific upslope area and β is the surface slope. In this study, 25 m spatial resolution from digital elevation models (DEM) data were used to investigate the scale-dependency of TWI values when converting DEMs to 50 and 100 m. To investigate the impact of different spatial resolution, the two lower resolution DEMs were interpolated to the original 25 m grid size. In addition, to compare different flow-direction algorithms, a second objective was to evaluate differences in spatial patterns. Thus the values of TWI were compared in two different ways: 1) distribution functions and their statistics;and 2) cell by cell comparison of DEMs with the same spatial resolution but different flow- directions. As in previous TWI studies, the computed specific upstream is smaller, on average, at higher resolution. TWI variation decreased with increasing grid size. A cell by cell comparison of the TWI values of the 50 and 100 m DEMs showed a low correlation with the TWI based on the 25 m DEM. The results showed significant differences between different flow-diretction algorithms computed for DEMs with 25, 50 and 100 m spatial resolution.展开更多
文摘This work studies the complementarity between hydro, wind and solar photovoltaic energy in the Brazilian state of Rio Grande do Sul. Brazil is a country highly dependent on hydro energy;however, the existent plants are not being able to cover the energy demand in recent years. In this context, the state of Rio Grande do Sul becomes important because of its potential for wind and solar photovoltaic energy, having complementarity between water, wind and solar photovoltaic schemes when hydroelectric reservoirs are at their lowest levels. This study aims to survey the complementarity of various parts of Rio Grande do Sul by proposing mathematical dimensionless ratios, focusing on intra-annual period to carry out a mapping of the entire state. It also analyses the ability to provide power supply throughout the year, through the stabilization of the energy supply, which depends on an adequate scale for photovoltaic, wind power and hydroelectric harnessing. According to the results obtained, the regions with the best complementarity indexes for deployment of a hybrid system in relation to water and wind power were the Metropolitan Region of Porto Alegre and the Southeast region, and the same regions also presented the best results for the complementarity between hydro and solar photovoltaic. Regarding wind and solar photovoltaic energy, the state’s northeast region presented the best results. Finally, the Northeast region of the state also presented the best results for the three energies together.
文摘Energetic complementarity has been studied in recent years and can be an important tool for managers to decide on the design and operation of hybrid systems based on renewable energy resources. Complementarity is an ability presented by two or more energy resources to complement each other over time. Complementarity can be verified in one place or at different places. This second case can be termed as spatial complementarity and is more complex than the complementarity in the same place, requiring a specific approach for its quantification This paper discusses concepts related to energetic complementarity and presents the basis for a method to evaluate energetic time-complementarity across space, applying the concepts presented to the northern coast of the state of Rio Grande do Sul, the southernmost state of Brazil.
文摘A variety of landscape properties have been modeled successfully using topographic indices such as topographic wetness index (TWI), defined as ln(a/tanβ), where a is the specific upslope area and β is the surface slope. In this study, 25 m spatial resolution from digital elevation models (DEM) data were used to investigate the scale-dependency of TWI values when converting DEMs to 50 and 100 m. To investigate the impact of different spatial resolution, the two lower resolution DEMs were interpolated to the original 25 m grid size. In addition, to compare different flow-direction algorithms, a second objective was to evaluate differences in spatial patterns. Thus the values of TWI were compared in two different ways: 1) distribution functions and their statistics;and 2) cell by cell comparison of DEMs with the same spatial resolution but different flow- directions. As in previous TWI studies, the computed specific upstream is smaller, on average, at higher resolution. TWI variation decreased with increasing grid size. A cell by cell comparison of the TWI values of the 50 and 100 m DEMs showed a low correlation with the TWI based on the 25 m DEM. The results showed significant differences between different flow-diretction algorithms computed for DEMs with 25, 50 and 100 m spatial resolution.
